Ground water has always been an important resource, and wells have been used through all of history to provide water for people to use for drinking, washing and so forth, and for agricultural uses. It has always been important to monitor the level of water in wells and to learn if the water table is falling because of a decrease in water being supplied to the aquifer or because of overuse of the ground water. The water table will fluctuate according to seasonal variations in rainfall and the many other factors. It has always been difficult to monitor the capacity of a water supply source to provide water, because of the complexity both in determining the inflow and outflows from the aquifer.
In modern times, water is pumped from bores that draw water from aquifers, and so it is easy to remove too much water. Generally many bores may share an aquifer and any one bore can deplete the aquifer in different ways from the others in the array, because the factors involved in water replenishment can vary considerably across all the bores, due to geographic features of the aquifer, the arrangement of rivers and streams on the surface, and different rainfall patterns over the area, for instance.
Monitoring bores are often drilled at a distance to the production bores, and are used to measure the head of groundwater, which is a measure of the level of the groundwater in the bore or the water pressure. In the past, water levels from monitoring bores often used to be measured once every six months or so. This was often done by measuring the water level inside a hollow, water-filled casing sunk into the ground, which has slots at its base to admit the water. A person would lower a weight on a tape measure, called a “plopper” that makes a noise when it touches the water surface, allowing the depth of water from the top of the casing to the water surface to be calculated. In more recent times, an electronic “logger” is often used, which achieves the same result, but which can also be wired to transmit the results to a base station. In the past, loggers were very rare or too expensive or often too unreliable to be much used, but in recent times the problems with using loggers have been overcome, and they are now becoming common. The measurements collected by these means are collated and then mapped using contouring so as to understand the flow conditions in an aquifer.
With the advent of loggers, it is now possible to precisely measure water levels on a continual basis, such as at daily, or hourly intervals or continuously, for example. The data can still be used to make water level maps which help to understand the direction of flow. However, with the greater use of loggers it is possible to get better quality and quantity of data, which can then be analysed in a number of ways.
In accordance with the invention, one avenue is to use this data as a new source of input for predictive modelling. Previously the data was plotted from individual bores (time series data) to understand how a particular point in the aquifer is behaving. It is now proposed, according the invention, is to use this data to quantify the level of stress that is being imposed on the aquifer system.
Accordingly, it would be useful to provide a solution that avoids or ameliorates any disadvantage present in the prior art, or which provides another and new alternative to the prior art approaches.